Establishing communications with a called party becomes a problem when that party is mobile. In general, persons wishing to contact a particular party initiate a call to a specific telephone associated with that party, such as the party's home telephone. A disadvantage of this method of communication is that parties are not always in close proximity to their home telephone, or for that matter, in close proximity to any telephone. This presents a problem to persons who need to contact the mobile party immediately, and regardless of that party's location.
Several technologies have developed in an effort to solve the problem of establishing communication with a mobile party. These include call forwarding, paging, and cellular systems. However, each of these technologies has drawbacks which prevent seamless and ubiquitous communication.
Call forwarding is a well-known technique whereby an individual who plans to be away from an associated telephone can redirect calls to an alternate telephone. For example, an office worker planning to go on vacation could redirect calls to an office mate's telephone. Such a system, although desirable, is inflexible. It requires that the forwarding party access a telephone to activate and deactivate the call forwarding, and to change the forwarding number. This inflexibility is particularly harsh on those parties that require frequent changes to their forwarding number, such as a traveling salesman who is on the road and would like to receive calls from potential buyers.
Moreover, present call forwarding schemes make inefficient use of network resources. Calls must be sent to the forwarding party's end office before they are redirected. Thus, for example, when a party forwards calls from the party's home telephone in California to a relatives telephone in New Jersey, calls from New York to the party's home telephone will be routed to California before being forwarded to New York. Such a process unnecessarily ties up network resources from New York to California to complete a call from New York to New Jersey.
In a paging system, a mobile individual carries a portable pager. Typically, the pager is assigned a telephone number and is capable of receiving a predetermined radio signal. When a caller dials the pager's number, the predetermined radio signal is broadcast and the pager responds to the signal by activating an audible and/or visual alarm. The alarm serves to alert the mobile individual that an attempt to contact her has been made. Often, the caller's telephone number will be included in the radio signal so that the pager can record the caller's number and the called party can initiate a return call at some later time. One of the drawbacks of past paging system is that they do not usually support two-way communication. Thus, in a typical paging scenario, the called party must relocate and initiate a return call to establish full two-way communication with the calling party. Such relocation may be inconvenient and untimely resulting in "telephone tag"--situations in which two individuals periodically try to contact one another and fail because the other person is unavailable.
Another drawback of past paging systems is the delay associated with the paging queue. In general, a paging service can only transmit one page at a time. However, a service usually receives many paging requests at once. Consequently, a queue builds up at the service's broadcast facility and a delay in paging throughput times results. This problem is compounded in paging services that offer national coverage to their subscribers. In such services a subscriber's pages are broadcast from several facilities, and therefore a delay in throughput times results at each facility.
Cellular systems offer an answer to the relocation problems present in call forwarding systems and paging systems but introduce a host of new problems. A typical cellular phone is a wireless two-way voice communication device that can be carried on an individual person. Typically, each cellular phone user subscribes to service with a carrier in a particular geographic region serviced by that carrier. Calls to the subscriber, when the subscriber is in the home region, are easily completed since such calls are routed through a Mobile Telephone Switching Office (MTSO) serving their home region. However, when a subscriber is located in a different region, the subscriber is designated a "roamer", and call completion becomes more difficult because it is not known, a priori, through which MTSO to route the call.
The roamer problem may be overcome by having the roaming subscriber notify the "home MTSO" that she will be located in another region. This allows the necessary information to be transmitted from the "home MTSO" to the "host MTSO" so that the "host MTSO" can route the subscriber's calls. This "cellular call forwarding", however, introduces problems similar to those associated with traditional call forwarding. Moreover, all cellular communications--including those within the home region suffer from a sensitivity to noise, precluding guaranteed high quality communications.
Given the problems associated with the prior call forwarding, paging, and cellular systems, there is a need to provide a system that will assure ubiquitous high quality communications with mobile parties.
The invention disclosed in patent application Ser. No. 08/379425, cited hereinabove, addresses the foregoing disadvantages in prior systems used to communicate with mobile individuals. The 08/379,425 application disclosed a system for communicating with a mobile individual having an assigned Personal Telephone Number (PTN) wherein the mobile individual is paged whenever calls are made to the PTN and uses a two-way pager to transmit a forwarding number for such received calls on a call by call basis. In this manner, the invention overcame the disadvantages of the prior systems.
The 08/379,430 application also disclosed a system which employed a two-way paging technique to overcome the disadvantages present in the prior systems used to communicate with mobile individuals, while minimizing the time required to establish such communication. In accordance with that invention, a mobile person is equipped with a two-way pager and assigned a PTN. The mobile person uses the pager to transmit a forwarding telephone number to a paging service. The paging service relays the forwarding number to a Customer Routing Point (CRP) where the number is stored. Thereafter, whenever a call is placed to the mobile person's PTN, the terminating number is retrieved from the CRP and is used to forward the call to a terminating telephone. The 08/379,430 invention further disclosed an alternative to the call forwarding technique of the 08/379,425. While the 08/379,425 invention disclosed a bridging or merging technique for the forwarding of calls, the 08/379,430 disclosed a rerouting technique for the forwarding of calls.
In sum, the 08/379,425 allows a mobile party to use a two-way pager to respond to calls on a "call by call" basis, designating a forwarding number for each call upon reception of a page announcing the call. The 08/379,430, in contrast, allows a mobile party to "register" a forwarding number so that calls are automatically forwarded to the registered number, thereby eliminating the need to page the mobile party upon receipt of each call. In accordance with the Foladare 3-14-8-13 invention, the party may still change the forwarding number wherever and whenever the party wants, but need not respond on a call by call basis.
While the "registration" mode of the 08/379,430 application invention provides quicker call routing than does the "call by call" mode of the 08/379,425 application, the flexibility provided by the call by call mode--allowing call forwarding tailored to each individual call--makes that mode attractive to many mobile users.
Many two-way pagers include, instead of or in addition to a keypad which can be used to manually enter forwarding- telephone numbers, a menu feature which provides a list of "speed-dial" options from which the mobile party can choose for forwarding calls on a call by call basis. These options might include, for example, "forward to office" or "forward to secretary." The use of such menus lessens the call routing delay associated with call by call mode.
The menus on available two-way pagers, however, often are capable of displaying only a limited number of options (e.g., 3 or 4). Furthermore, notwithstanding any pager-defined menu limitation, it would be cumbersome for the mobile party to have dozens of call forwarding options to scroll through each time an incoming page is received. On the other hand, limiting the menu to the same, static 3 or 4 options diminishes the utility of the call forwarding menu to the mobile party. Thus, it is desirable to make the menu options which are available on the two-way pager when the pager is in call by call mode easily configurable by the mobile party.